In order to understand a domain, you have to start with background information. The history of public relations begins in 1860s, when terms like “publicity”, “press agent” were put together with “business”, “industry” or “company”.
More PR history, here:
Ivy Lee is one of the pioneers of public relations, the one who in 1906 presented what today we call The Declaration of Principles.
This is Ivy Lee’s “Declaration of Principles,” as quoted by Sherman Morse in “An Awakening in Wall Street: How the Trusts, after Years of Silence, now speak though authorized and acknowledged Press Agents”(The American Magazine, vol. 63, September 1906). Update: vol. number was incorrect — the correct number is vol. 62. Page numbers = 457-63; the declaration is on p. 460.
“This is not a secret press bureau. All our work is done in the open. We aim to supply news. This is not an advertising agency; if you think any of our matter ought properly to go to your business office, do not use it. Our matter is accurate. Further details on any subject treated will be supplied promptly, and any editor will be assisted most cheerfully in verifying directly any statement of fact. Upon inquiry, full information will be given to any editor concerning those on whose behalf an article is sent out. In brief, our plan is, frankly and openly, on behalf of business concerns and public institutions, to supply to the press and public of the United States prompt and accurate information concerning subjects which it is of value and interest to the public to know about. Corporations and public institutions give out much information in which the news point is lost to view. Nevertheless, it is quite as important to the public to have this news as it is to the establishments themselves to give it currency. I send out only matter every detail of which I am willing to assist any editor in verifying for himself. I am always at your service for the purpose of enabling you to obtain more complete information concerning any of the subjects brought forward in my copy.”
Better tomorrow,
PR Pret-a-Porter.
PR Pret-a-Porter 
Comments on: "Declaration of Principles – Ivy Lee" (1)
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